Organic dielectric or conductive compounds on metal electrodes, especially on copper layers or copper-containing layers, are used, for example, in the production of organic-based electronic components.
For the purposes of miniaturization, it is particularly advantageous to use ultrathin layers, especially monolayers, with precisely adjusted functionality in electronic components, especially also in organic electronic components. In order that molecules in monolayers self-organize and hence exhibit maximum functionality and function density, it is advisable to fix them on the particular electrodes by head or anchor groups, which automatically results in an alignment of the linker groups, i.e. of the groups connecting the two ends. The attachment to the substrate takes place spontaneously provided that the substrate has been prepared appropriately.
The specific functionality is determined by the linkers and head groups. The anchor determines the self-organization.
For this purpose, DE 10 2004 005 082, for example, discloses an aromatic head group which has π-π interaction and whose introduction is chemically complex, which binds a self-assembled dielectric layer to an electrode. According to DE 10 2004 005 082, the attachment to the counterelectrode used, as what is called the anchor group of the organic dielectric compound, which is usable as a monolayer in a capacitor, is a silane compound which can be attached to the electrode via an oxide layer formed from a non-copper oxide.
A disadvantage of the known related art is that the electrode surface, i.e., for example, the copper surface, preferably has to be functionalized with aluminum or titanium for application of the self-assembled monolayer, the functionalization then providing an oxidic surface for attachment. However, such a functionalization step for the electrode surface is very costly, since non-copper metals first have to be applied and structured. An additional factor is that the electrode surfaces, if they are processed by conventional methods on conventional blanks or circuit boards or prepregs generally have a surface roughness in the region of approx. 4 μm. This roughness limits the mechanical stability of a surface coated with a monolayer, since the gaps at the particle boundaries are not necessarily fully covered, or high field strengths arise at substrate tips. The height of the monolayer, generally approx. 2 to 5 nm, and not more than 20 nm, does not planarize the roughness due to the conforming deposition.